The calorie intake calculator provides an estimate of how many Calories (or kilojoules) are required for both men and women.

■ To break this down into carbohydrates, protein, and fat - use the nutrient calculator.■ If you are looking to gain weight or muscle - use the bulking calculator.■ If you are pregnant and looking to gain the appropriate amount of weight needed for a healthy baby - see the pregnancy calorie calculator.■ If you are a new mother and are breastfeeding - see the breastfeeding calorie calculator.

Calories for Fat LossScience tells us that 1 pound of fat is equal to 3500 calories, so a daily calorie deficit of 500 should result in 1 pound per week fat loss. In reality things don't quite work that efficiently!

Warning!Always try to aim for the "Fat Loss" daily calorie level. The "Extreme Fat Loss" level is effectively a rock bottom calorie level. Do not attempt to immediately drop your calories to this level hoping for the quick fix - this may ultimately backfire. The Extreme Fat Loss level is listed to show the lowest calorie amount that could be considered. It should be seen as the exception rather than the rule.

It truly is better to burn the fat than to starve it.

The Weight Loss PlateauOver time our bodies adapt to the lowered calorie level. Our body becomes more efficient at using energy (lowered metabolism), and therefore burns less fat.This is why most of us reach a weight loss plateau. At this point, the only option is to boost metabolism; increased cardio, weight training, 'cheat' meals (i.e. ocassional high-calorie meals), cycling (or zig-zagging) calories, and even manipulating macro-nutrient ratios can all help to do this (don't forget adequate sleep and hydration). You often find that the nearer you get to your goal weight (or body fat percentage) - the harder things get!

Continually dropping calories only serves to lower metabolism even further - the moment you return to 'normal' eating - the weight comes back on.

Minimum Daily Calorie intakeIt is difficult to set absolute bottom calorie levels, because everyone has different body composition and activity levels. Health authorities do set some baselines - these are 1200 calories per day for women, and 1800 calories per day for men. This doesn't really make too much sense - are you are sedentary person with little muscle mass? Or someone who is tall, muscular, and exercises a lot? Absolute levels don't work - but do give us a starting point.When reducing calories:Try not to lower your calorie intake by more than 1000 calories below maintenance. Doing so may invoke the bodies starvation response, which can lead to the Yo-yo dieting effect.Try to gradually lower calories. A sudden drop (such as 500 calories or more) can cause your metabolism to slow.

What happens when calories are too low?1) Muscle mass is broken down for energy (catabolism).2) Metabolic rate will begin to drop (typically) after 3 days of very low calories - this is related to, and compounded by the loss of muscle mass.3) With very low calories you risk sluggishness, nutritional deficiencies, fatigue, and often irritability. You are completely set-up for a regain in fat if you suddenly return to your previous eating patterns.

How to Zig Zag Calories?As mentioned above, tricking the body by varying calorie intake can be helpful - particularly for those that have hit a plateau. Jon Benson's Every Other Day Diet is worth a look: rather than eating "diet food", he changes nothing but varies the amount he eats.

Carb CyclingTo extend the concept of calorie cycling even further, carbohydrate cycling is an option especially for those who have HIT A PLATEAU. This involves manipulating your daily intake of carbohydrates in order to maximize fat loss, and it helps to keep you in the right 'headspace' when you have 1-2 days of restricted Calories. Tom Venuto's article on Carb cycling is an excellent guide to start looking at.

How to Start ExercisingThis is intensely personal and it's very important to find something you enjoy doing. Walking is where most people begin, but a gym membership is also a good place to start (24 hour fitness has a useful guide to picking the right membership options).

Lose Fat AND Build Muscle?Most people lose muscle mass when restricting calories. It takes great effort to maintain muscle tone - and it is even more tricky actually building muscle while losing fat.

There are 2 great resources for this,

■ It's worth reading Tom Venuto's Burn the fat, feed the muscle (BFFM) for valuable insight on how to maintain muscle while maximizing fat loss. This book / manual is the biggest selling on-line book over the last 8 years.

■ To build muscle and lose fat check out Venuto's follow up - the Holy Grail Body Transformation Program. It is an honest guide showing you how to achieve this. It is technical - using cyclical diet adjustment and periodization techniques. Please note that this takes great dedication!ReferencesThis calculator has been developed using the most accurate methodologies from peer-reviewed research. Please see the Calorie Needs Guide for a complete explanation + citations.

------------------------------------------------------

Note,If you want to do it by yourself, here are some tips,

#how to alculate Your BMI,

Your BMI is the amount of energy your body needs to function. We use about 60% of the calories we consume each day for basic bodily functions such as breathing.

>(BMI= 703 X (weight (pounds) / height (inches)2)).

#Some of the facts that influence your BMI are height, weight, age and sex.